asimnzr / fakeIndexedDB

A pure JS in-memory implementation of the IndexedDB API

Fake IndexedDB

This is a pure JS in-memory implementation of the IndexedDB API.

It passes the W3C IndexedDB test suite (a feat that all browsers except Chrome fail) plus a couple hundred more tests just to be sure. It also works well enough to run fairly complex IndexedDB-based software.

Installation

For use with CommonJS (Node.js/io.js/Browserify), install through npm:

$ npm install fake-indexeddb

Otherwise, download the bundled version and include it in your page like:

<script type="text/javascript" src="fakeIndexedDB.js"></script>

If you're using AMD, you'll have to shim it.

Use

Functionally, it works exactly like IndexedDB except data is not persisted to disk.

Example usage:

var fakeIndexedDB = require('fake-indexeddb');
var FDBKeyRange = require('fake-indexeddb/lib/FDBKeyRange');

var request = fakeIndexedDB.open('test', 3);
request.onupgradeneeded = function () {
    var db = request.result;
    var store = db.createObjectStore("books", {keyPath: "isbn"});
    store.createIndex("by_title", "title", {unique: true});

    store.put({title: "Quarry Memories", author: "Fred", isbn: 123456});
    store.put({title: "Water Buffaloes", author: "Fred", isbn: 234567});
    store.put({title: "Bedrock Nights", author: "Barney", isbn: 345678});
}
request.onsuccess = function (event) {
    var db = event.target.result;

    var tx = db.transaction("books");

    tx.objectStore("books").index("by_title").get("Quarry Memories").addEventListener('success', function (event) {
        console.log('From index:', event.target.result);
    });
    tx.objectStore("books").openCursor(FDBKeyRange.lowerBound(200000)).onsuccess = function (event) {
        var cursor = event.target.result;
        if (cursor) {
            console.log('From cursor:', cursor.value);
            cursor.continue();
        }
    };
    tx.oncomplete = function () {
        console.log('All done!');
    };
};

Variable names of all the objects are like the normal IndexedDB ones except with F replacing I, e.g. FDBIndex instead of IDBIndex.

If you're using the bundled version (not installed through npm), then all of the variables are created and attached to window, like window.fakeIndexedDB, window.FDBKeyRange, etc.

Potential applications:

1. Use as a mock database in unit tests.

2. Use the same API in Node.js/io.js and in the browser.

3. Support IndexedDB in old or crappy browsers.

4. Somehow use it within a caching layer on top of IndexedDB in the browser, since IndexedDB can be kind of slow.

5. Abstract the core database functions out, so what is left is a shell that allows the IndexedDB API to easily sit on top of many different backends.

6. Serve as a playground for experimenting with IndexedDB.

License

Apache 2.0